Sony Corporation

Tetsuo Usui

Akio Yamakawa

Masamichi Utsumi

There is disclosed a method of playing back information from an optical multilayer disk having a plurality of recording disks stacked on top of each other, by the use of an optical pickup device. In order to switch the focused recording layer from a first one to a second one so that data is read from the second recording layer, the focus balanced condition of the pickup device is switched from a setting providing a focus error characteristic adapted for the first recording layer to a reference setting providing a neutral focus error characteristic. Then, the focal point of the pickup device is moved from the first recording layer. Subsequently, the pickup device is focused onto the second recording layer, and data is read from the second recording layer. Thereafter, the focus balanced condition of the pickup device is switched to a setting adapted to the second recording layer.

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Tokyo, Japan

Tetsuo Usui